Wet mate connector

ABSTRACT

A connector has first and second connector units, each unit incorporating an oil-filled chamber housing one or more contact elements to be joined. At least one connector unit has a face seal assembly which seals the forward end of the contact chamber in the unmated condition. The face seal assembly comprises three elements. One element is an annular elastomeric seal situated radially outward. The two other elements are inner seal elements which are pressed together radially to form a substantially disc-like shape. The resulting disc-like shaped seal fills the central, circular end face opening of the outer annular seal. As the connector units are mated, elements of the elastomeric face seal assembly are displaced, one axially, and others both axially and radially, creating an opening between the oil-filled chambers that is sealed from the outside environment.

RELATED APPLICATION

The present application claims the benefit of co-pending U.S.provisional patent application No. 60/974,757, filed Sep. 24, 2007, thecontents of which are incorporated herein by reference in theirentirety.

BACKGROUND

1. Field of the Invention

The present invention relates generally to connectors which can be matedand unmated in a harsh environment, such as underwater.

2. Related Art

There are many types of connectors for making electrical and fiber-opticcable connections in hostile or harsh environments, such as underseaconnectors which can be repeatedly mated and demated underwater at greatocean depths. These connectors typically consist of plug and receptacleunits or connector parts, each attached to cables or other devicesintended to be joined by the connectors to form completed circuits. Tocompletely isolate the contacts to be joined from the ambientenvironment, one or both halves of these connectors house the contactsin oil-filled, pressure-balanced chambers.

Both the plug and receptacle halves of most fiber-optical connectorswhich are mateable in a harsh environment have oil-filled chambers. Thechambers are typically brought face-to-face during an early step of themating sequence. In a subsequent mating step, one or more connectivepassages, sealed from the outside environment, are created between thechambers of the mating connector halves. The passages join the twooil-filled chambers, creating a single, connected oil volume. Actualconnection of the contact junctions then takes place within the commonoil chamber. There are several patented examples of such connectors,such as U.S. Pat. Nos. 4,682,848; 5,738,535; 5,838,857; 6,315,461, and6,736,545.

Some such existing connectors work very well. The technology isrelatively new, however, and there is still much room for improvement.In particular, the existing products are complex, expensive, and theirreliability is not flawless.

Therefore, what is needed is a system and method that offersimprovements in complexity, performance, and reliability and reduces orovercomes these significant problems found in prior wet mate connectorsas described above.

SUMMARY

Embodiments described herein provide a new wet mate or harsh environmentconnector.

In one embodiment, a connector has first and second connector units orplug and receptacle units, each unit incorporating an oil- or otherfluid-filled contact chamber housing one or more contact elements to bejoined. Each oil chamber is pressure balanced to the outside environmentby way of flexible elements that adjust the chamber's size to compensatefor volumetric changes of its contents. When the connector units aremated, axially opposed elastomeric face seal assemblies of the units arepressed together, completely sealing the plug-receptacle interface fromthe outside environment. As the mating sequence proceeds, elements ofthe elastomeric face seal assemblies are displaced, some axially, andothers both axially and radially, creating an opening between theoil-filled chambers that is sealed from the outside environment.

In one embodiment, the face seal assemblies of both connector unitscomprise three elements. One element is an outer annular elastomericseal situated radially outward. The two other elements, viewed from themating faces of the connectors, appear as a diametrically splitelastomeric disc, or two elastomeric disc halves of substantiallyhalf-circular shape that are pressed together radially to form afull-circular shape. The resulting inner seal fills the central,circular opening at the forward end of the outer annular seal. Thus, thecompleted sealing face of each unmated connector half comprises thethree elements radially squeezed together to form a single unit thatcompletely encloses its mating face.

As the connector halves are mated, their opposing elastomeric facespress against each other axially, sealing the entire plug-receptacleinterface from the outside environment. The next step in the matingsequence finds the pressed-together, split, disc-shaped inner sealsdisplaced axially inwardly into the receptacle, away from the annularouter seals. As the split seals move inwardly, they enter a largerdiameter bore within the receptacle that allows their separatehalf-circular discs to spring radially outward, away from each other,thus creating an open path between the inner faces of the half-circulardiscs oriented along the axial centerline of the mated connector units.The action effectively creates an open passageway between the two oilchambers when the plug and receptacle halves are mated. The interfacebetween the plug and receptacle units remains sealed from the outsideenvironment by the pressed-together annular outer seals.

In a subsequent step of the mating sequence, one or more contact probesfrom one of the connector units effectively pass through the openpassageway and into the other connector unit, where they join with oneor more respective contacts to create one or more completed circuitswithin the common, pressure-balanced oil bath.

The connector de-mating sequence is just the reverse of the matingsequence. When de-mating, the one or more contact probes disconnect fromthe respective one or more contacts in the other connector unit, movingaxially away from them, and withdrawing back through the annular outerseal and into the body of the respective connector unit. Thehalf-circular disc-shaped seal elements then move together radially toform full-circular discs, and move axially to fill the central openingsof their respective annular outer seals. That action effectively sealsthe individual plug and receptacle end faces, while the plug-receptacleinterface between the connector units still remains sealed from theoutside environment by the still pressed-together annular outer seals.Next, the plug and receptacle units separate, removing the spring forcesthat pressed the annular outer seals together, and the twoindividually-sealed connector units are disconnected.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of the present invention, both as to its structure andoperation, may be gleaned in part by study of the accompanying drawings,in which like reference numerals refer to like parts, and in which:

FIG. 1A is a perspective view of a first connector unit or plug unit ofone embodiment of a connector, shown in the unmated condition;

FIG. 1B is a perspective view of a second connector unit or receptacleunit for releasable mating engagement with the plug unit of FIG. 1A,with the receptacle unit shown in the unmated condition;

FIG. 2 is a partial axial cross-section of the unmated plug unit of FIG.1A;

FIG. 3 is a perspective view of the plug inner seal assembly in theunmated condition;

FIG. 4 is a perspective view of the plug inner seal assembly in themated condition;

FIG. 5 is a perspective view of the plug annular end seal assembly;

FIG. 6 is a perspective view of the plug contact assembly;

FIG. 7 is a perspective view of the receptacle contact assembly;

FIG. 8 is a partial axial cross-sectional view of the unmated receptacleunit of FIG. 1B;

FIG. 9 is a perspective view of the unmated receptacle inner sealassembly;

FIG. 10 is a perspective view of the mated receptacle inner sealassembly;

FIG. 11A is a front perspective view of the receptacle outer annular endseal;

FIG. 11B is a rear perspective view of the receptacle outer annular endseal; and

FIG. 12 is a partial axial cross-sectional view of the mated connector.

DETAILED DESCRIPTION

Certain embodiments as disclosed herein provide for a wet mate or harshenvironment connector which may be mated and unmated in a wetenvironment or underwater, or in other harsh conditions, and has contactchambers which are sealed both in the mated and unmated conditions.Although the disclosed embodiments are concerned with a fiber-opticalconnector, the optical junctions may be replaced by electrical junctionsto form an electrical connector, or by electro-optical junctions to forma hybrid electro-optical connector in alternative embodiments. Althoughthe connector is described as a wet mate connector, the language “wetmate” should be interpreted to include connectors used in all kinds ofharsh conditions.

After reading this description it will become apparent to one skilled inthe art how to implement the invention in various alternativeembodiments and alternative applications. However, although variousembodiments of the present invention will be described herein, it isunderstood that these embodiments are presented by way of example only,and not limitation. As such, this detailed description of variousalternative embodiments should not be construed to limit the scope orbreadth of the present invention.

FIGS. 1 to 12 illustrate an optical connector comprising releasablymateable first and second connector units or plug and receptacle units2, 1. FIGS. 1A and 1B illustrate the first connector or plug unit 2 andthe second connector or receptacle unit 1, respectively, in an unmatedor disconnected condition. Each connector unit has an outer rigid shell4, 3, with terminal nut 6, 5, respectively. A sealed chamber 60, 58 inthe receptacle unit 1 (see FIG. 8) encloses contacts of a receptaclecontact assembly 56 illustrated in FIG. 7, while a sealed chamber 22 inthe plug unit 2 (see FIG. 2) encloses contacts of a plug contactassembly 24 illustrated in FIG. 6. Openings at the outer or forward endsof the respective contact chambers are sealed by face seal assemblies,and the outer or exposed ends of the face seal assemblies are visible inFIGS. 1A and 1B. The plug face seal assembly comprises a first or plugouter annular seal 10 (see FIG. 5) and a first or plug inner sealcomprising seal elements 13 and 14 (illustrated in more detail in FIGS.3 and 4). The receptacle face seal assembly comprises a second orreceptacle outer annular seal 9 (see FIGS. 11A and 11B), and a secondinner seal comprising receptacle seal elements 11 and 12 (illustrated inmore detail in FIGS. 9 and 10).

When the plug and receptacle or connector units 2, 1 are unmated as inFIGS. 1A, 1B, 2 and 8, the inner seal elements are positioned inside therespective outer annular seals which urge them into a sealed, closedcondition, as described in more detail below in connection with FIGS. 2to 12. When the plug and receptacle units are moved into matingengagement, smaller diameter portion 7 of receptacle shell 3 enters bore8 of plug shell 4. As mating proceeds, receptacle outer annular seal 9presses sealably against plug outer annular seal 10, and receptacle sealelements 11, 12 (FIGS. 9 and 10) press against plug seal elements 13 and14 (FIGS. 3 and 4). Keyway 15 in receptacle shell 3 cooperates with aninwardly projecting key 20 (shown in FIG. 2) in plug shell 4 duringmating to maintain rotational alignment of the mating connector halves.

Each outer annular seal 10, 9 has a tapered inner diameter or throughbore 45, 86, respectively, as illustrated in FIGS. 2, 8, and 11. Eachseal element has a tapered outer diameter designed for sealed matingengagement with the tapered inner diameter or through bore of therespective outer seal in the unmated condition of the plug andreceptacle units. As illustrated in FIGS. 2 and 3, the seal elements 13,14 of the plug unit in the unmated condition have an outwardly taperedouter diameter 46 extending up to their front end faces. The sealelements of the receptacle unit have an inwardly tapered outer diameter84 extending up to their front end faces, as illustrated in FIGS. 8 and9. The co-operation of the various parts of the seal assembly and therespective plug and receptacle shells as the units are moved into theunmated condition is described in more detail below, in connection withFIGS. 2, 3, 9, 10, and 12. Each seal element has a half-disc like shapewith a flat diametrical face or seal face for sealing engagement with anopposing flat diametrical face of the other seal element of therespective pair, as described in more detail below in connection withFIGS. 3, 4, 9, and 10.

An axial cross-sectional view of unmated plug unit 2 is illustrated inFIG. 2. Outer annular seal 10 forms part of an annular end seal assembly44 illustrated in more detail in FIG. 5 and described in detail below.Outer annular seal 10 is bonded or otherwise suitably attached toseal-support 16, and seal-support 16 and annular seal 10 are movablymounted in bore 17 of the plug shell. Outer annular seal 10 has atapered inner diameter or through bore 45, as noted above. Seal-support16 is generally circular in cross section and has an enlarged endportion 18 and a reduced diameter tubular portion 39 extending rearwardsfrom the end portion 18. Seal-support 16 serves a number of functions.Larger diameter portion 18 rides loosely in bore 17 of plug shell 4 inwhich it is free to move rearward against spring 19. Spring 19 seatsagainst shoulder 51 of seal-support 16 on its forward end and againstface 53 at the base of plug contact assembly 24 on its rearward end.Spring 19 urges seal-support 16 outward to the point where the taperedinner diameter of annular seal 10 sealably engages the tapered outerdiameters 46 of inner seal elements 13 and 14, which are substantiallyfixed in axial position. The forward travel of seal 10 is stopped whenits tapered inner diameter 45 sealably engages tapered outer diameter 46formed by the pressed-together seal elements 13, 14. Shoulder 21 formedby the transition between bores 8 and 17 in plug shell 4 provides asecondary, back-up stop to limit the outward travel of seal 10.

Seal-support 16 also provides attachment points for one end of a tubularflexible wall or bladder 23 which defines an oil-filled contact chamber22, as well as for a sleeve 27, and also acts as a forward seat forspring 19. Tubular portion 39 of seal seat or support 16 acts as asquirm guide for spring 19. Vent holes 40 in tubular portion 39 ensureadequate ventilation through the tubular section's walls. Alignment key54 cooperates with keyway 55 in plug shell 4 and keyway 155 (see FIG. 6)in the base of plug contact assembly 24 keep plug contact assembly 24rotationally aligned with shell 4.

Oil chamber or plug contact to chamber 22 is a volume enclosed byflexible wall 23 and seal-support 16 on its outer diameter, by face 53of plug contact assembly 24 on its rearward end, and by seal elements13, 14 and outer annular seal 10 on its forward end. Flexible wall 23 issecured between the base of plug contact assembly 24 and end portion 18of the seal support 16. Flexible wall 23 has a shoulder 28 at itsforward end seated in a groove or seat 29 in the outer diameter ofseal-support 16. Sleeve 27 serves to keep shoulder 28 engaged in seat 29of seal-support 16. Sleeve 27 is retained in position by snap fit intoseat 30 of seal-support 16. Shoulder 31 on the rearward end of flexiblewall 23 engages groove 32 in base 124 of plug contact assembly 24, andis retained in that groove by bore 17 of plug shell 4.

Vent holes 25 in shell 4 allow the outside environment to act againstflexible wall 23 so that the pressure within the enclosed volume of oilremains substantially the same as that outside of the oil volume. Nut 6cooperates with plug shell 4 to rigidly contain the various other plugcomponents.

Optical plug contact assembly 24 shown in more detail in FIG. 6 issubstantially identical to that described in U.S. patent applicationSer. No. 11/279,474 filed on Apr. 12, 2006, and U.S. Pat. No. 7,244,132issued on Jul. 17, 2007, the contents of both of which are incorporatedherein by reference. As illustrated in FIG. 6, contact assembly 24 has arigid base 124 and a tubular extension 26 of rectangular cross-sectionextends from base 124 into the oil chamber 22. An optical fiber ribbon126 is guided inside extension 26 and terminates in an optical ferruleor element 93 recessed inwardly from the open end of extension 26. Baseor rear end 124 of the plug contact assembly 24 has spaced mountinggrooves 32, 38 and 138 on its outer surface, as best illustrated in FIG.6.

FIGS. 3 and 4 show the plug inner seal assembly 73 in the unmated andmated conditions, respectively. Seal elements 13, 14 of elastomericmaterial are bonded or otherwise suitably attached to respective backplates 33, 34, which, in turn, are rigidly formed as a unit withstand-off tine pairs 42 and 35. The tines are forward extensions of tinebase 36, which is snap mounted by rearward directed fingers 37 to groove138 in base 124 of plug contact assembly 24, as illustrated in FIG. 2.The seal elements 13, 14 are therefore at a substantially fixed axialposition in bore 17. Rectangular extended portion 26 of plug contactassembly 24 (FIG. 6) extends from base or rear end 124 through arectangular opening 41 in tine base 36 (FIG. 3), which serves torotationally orient the split-disc seal assembly to the other componentsof the plug assembly. Each seal element 13, 14 is generally half-discshaped, with a tapered outer surface for sealing engagement with thetapered through bore 45 in outer annular seal 10. The outer or forwardend faces of the seal elements 13, 14 are of semi-circular shape, asseen in FIGS. 1A, 3 and 4, and elements 13, 14 have opposing,substantially flat inner diametrical faces or seal faces 102, as seen inFIG. 4.

In the unstressed, mated condition of FIG. 4, tine pairs 35 and 42project directly outward, perpendicular to face 43 of tine base 36, andthe seal elements 13, 14 are spaced apart to leave a gap or space 92between their inner diametrical faces 102. In the unmated condition ofFIGS. 2 and 3, elastomeric seal elements 13 and 14 are pressed togetherradially by tapered bore 45 of annular seal 10, so that diametricalfaces 102 are in face-to-face sealing engagement, and tine pairs 35 and42 are simultaneously bent or displaced toward each other. When thusbent, the tines have a modest residual spring force directed radiallyoutward.

Seal elements 13, 14 are held rigidly forward from face 53 of plugcontact assembly 24 by tine pairs 35, 42. Annular end seal assembly 44(FIG. 5), on the other hand, is forced axially inward by the receptacleduring mating, further compressing spring 19.

FIG. 5 is a perspective view of the plug annular end seal assembly 44.The assembly consists of outer annular seal 10 and seal-support 16. Seal10 is bonded or otherwise suitably attached to seal-support 16. Outerannular seal 10 is made from an elastomeric material. It has a taperedinner bore 45 which is tapered outwardly from the inner to the outer orfront end of seal 10. Seal elements 13, 14 have a correspondingoutwardly tapered outer diameter or surface 46 (see FIG. 3). A raisedinner annular surface portion 47 of the end face of seal 10 whichsurrounds bore 45 protrudes slightly outward axially from a surroundingouter annular surface portion 48 (see FIGS. 2 and 5). Surface portion 47is the area of the annular outer seal that sealably engages acorresponding end portion 88 (FIG. 11) of the end face of receptacleouter annular seal 9 during mating. Groove 49 separates annular innerand outer end surface portions 47 and 48 of the seal 10 and providesspace for the inner seal portion to expand outward radially when pressedaxially against its receptacle counterpart 9. Centering ribs 50 on theouter surface of seal 10 keep assembly 44 centered in bore 17 of plugshell 4 as the assembly moves axially within the bore during mating andde-mating.

An axial cross-sectional view of unmated receptacle 1 is shown in FIG.8, while various individual parts of the receptacle are illustrated inFIGS. 7 and 9 to 11. As illustrated in FIGS. 1B and 8, the shell 3 ofreceptacle unit 1 has a reduced diameter forward end portion 7 and alarger diameter rear end portion 3 separated by shoulder 97 which has atapered outer portion and a small inner annular portion 97A. Receptacle1 has a through bore of stepped diameter having a shoulder 69 betweenthe larger and smaller diameter portions 100, 58 of the bore. An oilchamber 60 is defined in the through bore by cooperating outer annularseal 9 and inner seal elements 11 and 12 on its forward end, by face 55of a base or end portion 156 of the receptacle contact assembly 56 onits rearward end, and by bore portion 58 and flexible tubular element orbladder 57 of a compensator 59 in bore portion 100 on its outerperimeter. Shoulder 61 of compensator 59 is seated sealably in groove 62on the outer surface of the end portion 156 of receptacle contactassembly 56 on its rearward end, and shoulder 64 of the compensatorlikewise seats in groove 63 of a compensator support 65 on its forwardend. Bore portion 100 of receptacle shell 3 retains the bladdershoulders 61 and 64 in their respective grooves. Four stand-off rods 66seat in four respective counter-bores 67 of compensator support 65 atone end and respective counter-bores 68 (FIG. 7) of end portion 156 ofcontact assembly 56 at the opposite end, maintaining correct axialspacing of the compensator support. Although the illustrated embodimenthas four stand-off rods 66 and associated bores, a greater or lessernumber of stand-off rods and associated bores may be used in alternativeembodiments. Terminal nut 5 and shoulder 69 of receptacle shell 3 retainthe compensator assembly, consisting of the compensator, stand-off rodsand compensator support, as well as the receptacle contact assembly 56,contained in position. Annular outer seal 9 is bonded or otherwisesuitably attached to the surfaces of cavity or recess 87 in the forwardend of receptacle shell 3. An inwardly tapered bore portion 85 in bore58 extends up to recess 87. As best illustrated in FIGS. 11A and 11B,receptacle outer annular seal 9 has an inwardly tapered bore 86extending from its rear end to forward end face 88, and an inwardlytapered end portion 89 on the outer surface of end seal 9 extends up toend face 88.

Annular end face 88 of receptacle outer annular seal 9 protrudes outwardbeyond the end of receptacle shell 3 when installed, as illustrated inFIG. 8. End face 88 sealably presses against corresponding end faceportion 47 of plug outer annular seal 10 when the connector halves aremated, as described in more detail below. Tapered portion 89 on theouter surface of receptacle outer annular seal 9 provides an annularspace 90 into which the elastomeric outer annular seal 9 can expandradially when pressed axially against surface portion 47 of plug outerannular seal 10.

Receptacle contact assembly 56 is illustrated in more detail in FIG. 7and comprises base or end portion 156 which is secured at the rear endof bore portion 100, and a tubular guide portion 80 of rectangular shapewhich extends from base 156 into the oil-filled chamber 60. The contactassembly 56 is of similar construction to the plug contact assembly 24.Optical ribbon fiber 180 extends through guide portion 80 and terminatesin an optical contact ferrule or contact element 94 which is housed inreduced cross-section forward end portion 98 of guide portion 80, asbest seen in FIG. 8.

Construction of receptacle inner seal assembly 74 (FIGS. 9, 10) is verysimilar to that of corresponding plug inner seal assembly 73 (FIGS. 3,4). FIGS. 9 and 10 illustrate the receptacle inner seal assembly 74 inthe unmated and mated conditions, respectively. Seal elements 11, 12 ofhalf disc-like shape are bonded or otherwise suitably attached torespective back plates 75, 76, which, in turn, are rigidly formed as aunit with stand-off tine pairs 77 and 78. Seal elements 11, 12 are ofsimilar half disc-like shape to the plug seal elements 13, 14, and havesemi-circular outer end faces. However, outer surface 84 in the matedcondition of FIG. 9 is tapered inwardly up to the outer end faces ofelements 11, 12, rather than outwardly, as is the case with elements 13,14 of the plug inner end seal assembly. The tines 77, 78 are forwardextensions of tine base 79. Rectangular opening 81 in tine base 79 (FIG.9) engages over the rectangular guide portion 80 of receptacle contactassembly 56 (FIG. 7), which serves to rotationally orient inner sealassembly 74 to the other components of the receptacle assembly. At thesame time, tine base 79 is free to travel within fixed limits onrectangular guide portion 80 (FIG. 7) of receptacle contact assembly 56.In the unstressed, mated condition of FIG. 10, tine pairs 77, 78 projectdirectly outward, perpendicular to face 82 of tine base 79, and the sealelements 11, 12 are spaced apart to leave a gap or space 91 betweentheir inner diametrical faces or seal faces 95. In the unmated conditionof FIGS. 8 and 9, elastomeric seal elements 11 and 12 are pressedtogether radially by tapered bore 86 of annular seal 9, so that faces 95are in face-to-face sealing engagement, and tine pairs 77 and 78 aresimultaneously bent toward each other. When thus bent, the tines have amodest residual spring force directed radially outward.

As illustrated in FIG. 8, the rear portion or tine base 79 of the innerseal assembly 74 seats against shoulder 83 at the base of a tubularcavity of spring-seat 72. The forward end of a spring 70 seats againstshoulder 71 at the forward end of spring-seat 72, and the rear end seatsagainst the base 156 of contact assembly 56 in groove 73 (FIG. 7).Spring 70 urges the spring seat and inner seal assembly 74 forward. Asspring 70 forces the inner seal assembly 74 into tapered bore portion 85of receptacle shell 3, inner seal elements 11, 12 are forced togetherradially, bending tine pairs 77 and 78 together, as illustrated in FIG.9. The inner seal assembly travels forward until the tapered outersurface 84 of the seal elements 11, 12 is in sealing engagement withcorresponding tapered inner surface or bore portion 86 of receptacleouter annular seal 9 (FIGS. 8 and 9). Backup plates 76 and 75 cannotpass through the opening at the forward end of tapered bore 85 of thereceptacle shell, thus providing a secondary back-up stop for theforward motion of inner seal assembly 74.

As the plug and receptacle units 2, 1 are moved into mating engagement,reduced-diameter portion 7 of the receptacle shell enters bore 8 of theplug shell. Plug shell alignment key 20 finds receptacle shell keyway15, moving the connector halves into rotational alignment. As matingproceeds, annular end face 88 of receptacle outer annular seal 9 pressesagainst raised annular end surface portion 47 of plug outer annular seal10, and the end faces of seal elements 11, 12 of receptacle inner sealassembly 74 are pressed against corresponding end faces of the opposingseal elements 13, 14 of plug inner seal assembly 73. Axially directedpressure of the various sealing element faces against each othercontinues to increase until it is sufficient to overcome the pre-load onplug spring 19, causing plug annular end seal assembly 44 to move inwardwithin the plug shell. Simultaneously, plug inner seal assembly 73forces receptacle inner seal assembly 74 inward, further compressingspring 70. The arrangement is such that all of the seals are pressedtogether before there is any movement of the rigid, spring-drivenmechanism. The overall effect is that both the plug and receptacle outerannular seals 10, 9 move into the plug shell 4, while simultaneouslyboth pairs of generally half disc-shaped seal elements 11, 12 and 13, 14move into the receptacle shell. As the annular seals and disc-shapedseal elements move away from each other, a central, tapered,through-bore 99 (FIG. 12) formed by the pressed-together outer annularseals 9 and 10 is completely open, thereby permitting free communicationbetween the plug and receptacle oil volumes, and also permitting theseals 9, 10 to pass over contact element 93 of the plug contactassembly. The forward faces of the pair of seal elements 13, 14 remainpressed against the corresponding faces of the opposing pair of sealelements 11, 12 throughout the mating process, and in the fully matedconnector. Although they are pressed together, the opposed faces do nothave to seal anything. They simply have to remain pressed together toretain in place any material trapped between them at the beginning ofthe mating process.

As the pairs of half disc-shaped seal elements 11, 12 and 13, 14 moveinto the receptacle, they pass through the enlarging tapered section 85of receptacle shell 3. Tine pairs 35, 42 and 77, 78 of the plug andreceptacle, respectively, spring radially outward into the matedcondition of FIGS. 4 and 10, creating aligned gaps 92, 91, respectively(FIGS. 4, 10 and 12) between the half disc-shaped seal elements. Contactelement 94 of receptacle contact assembly 56 is then free to passthrough gaps 91, 92 as the forward end portion of the receptacle unitcontinues to move into the plug shell, completing the optical junctionswith contact element 93 of plug contact assembly 24.

The mated connector is shown in FIG. 12. Insertion of the receptacleinto the plug shell is stopped when annular end portion 96A of plugshell 4 bottoms out against inner annular portion 97A of the shoulder 97of receptacle shell 3, leaving a small gap between hard stops of thecontact junctions.

The connector de-mating sequence is the reverse of the mating sequence.When de-mating, the one or more plug contacts disconnect from therespective one or more receptacle contacts, moving contact element orferrule 94 axially away from contact element 93, and withdrawing contactelement 94 back through the spaces 91, 92 between the inner end faces ofseal elements 11, 12 and 13,14, respectively. As the receptacle unit isretracted out of the plug shell, the inner, disc-shaped seal elements11, 12 of the receptacle are urged axially outwardly by spring 70 andmove into the bore portion 86 in the respective outer annular sealmember 9 as the smaller diameter end 7 of the receptacle starts toretract out of the forward end portion 8 of the plug bore. At the sametime, the outer annular seal member 10 of the plug is urged by spring 19back over the inner seal elements 13, 14. Each pair of half disc-shapedseal elements is urged together radially to close the gaps 91 and 92 andform full-circular discs which fill the central openings of theirrespective annular outer seals before the plug and receptacle halves aredisconnected. That action effectively seals the individual plug andreceptacle end faces, while the plug-receptacle interface betweenconnector halves still remains sealed from the outside environment bythe still pressed-together annular outer seals. Next, the plug andreceptacle separate, removing the spring forces that pressed the annularouter seals together, and the two individually-sealed connector halvesare disconnected.

The opening between plug and receptacle oil volumes in the aboveconnector is created in a unique way when the connector halves aremated. The half-circular disc-shaped inner seal elements allow freecommunication between oil volumes as soon as they are axially displacedfrom their respective annular outer seals. The construction requiresless relative axial motion of the plug and receptacle contacts than someprior art constructions to create an opening between the connectorhalves for the mating contacts to pass. This is because the halfdisc-shaped seals spring radially outward very quickly as the receptacleenters the plug.

The connector described above has improved internal ventilation due tothe larger opening between the oil volumes as compared to some prior artarrangements, allowing free and immediate oil communication between thechambers. As soon as the disc-shaped seals move axially, oil is free tomove past them from one chamber to the other. They remain pressedtogether axially, and begin to separate radially, too; but they are nolonger sealably seated in the annular outer seals, so oil can flowaround them. The mate/demate forces are reduced since the design avoidsthe need to overcome high stress O-ring seals or tightly squeezingsphincter-type seals, all of which require higher spring forces than theabove construction. The mating stroke is shorter, since the splitdisc-type end seals move out of the way earlier in the mating sequenceand move transversely apart to provide the opening between the oilchambers through which the mating contacts are free to pass. This allowsa reduction of the axial space between the contacts and thus a shortermating stroke. Due to the shorter mating stroke, the overall matedlength of the connector is also reduced, as is the unmated length ofeach connector part. The mechanical action is relatively simple andreliable, and produces relatively low stress on the elastomeric parts,as compared to some prior art connectors which require a great deal ofstretch on the elastomers forming the seals, limiting the choice ofelastomers. This construction allows choice of the seal material from alarge range of elastomers with enhanced chemical resistance. At the sametime, the connector uses the same optical interfaces and fiberfeed-through capillaries as existing connectors. Overall, the componentsof this connector are relatively simple and fewer components arerequired than at least some prior art connectors.

The above description of the disclosed embodiments is provided to enableany person skilled in the art to make or use the invention. Variousmodifications to these embodiments will be readily apparent to thoseskilled in the art, and the generic principles described herein can beapplied to other embodiments without departing from the spirit or scopeof the invention. Thus, it is to be understood that the description anddrawings presented herein represent a presently preferred embodiment ofthe invention and are therefore representative of the subject matterwhich is broadly contemplated by the present invention. It is furtherunderstood that the scope of the present invention fully encompassesother embodiments that may become obvious to those skilled in the artand that the scope of the present invention is accordingly limited bynothing other than the appended claims.

1. A connector, comprising: a first connector unit having a firstcontact chamber and a first contact assembly within the first contactchamber; a second connector unit having a second contact chamber and asecond contact assembly within the second contact chamber; each contactchamber having a forward end opening; the connector units being movablebetween an unmated condition and a mated condition in which they are inreleasable mating engagement and the first and second contact assembliesare in communication; at least one elastomeric face seal assembly whichseals the forward end opening of one of the contact chambers in theunmated condition of the connector units, the face seal assemblycomprising a first outer annular seal having a through bore and a firstinner seal having a first pair of separate inner seal elements havingouter surfaces and opposing seal faces; one of said seals being movablerelative to the other seal between a sealed condition in which the outersurfaces of the inner seal elements are in sealing engagement with thethrough bore of the outer annular seal when the connector units areunmated and an open condition in which the inner seal elements arespaced from the outer annular seal when the connector units are mated;and the opposing seal faces of the inner seal elements being radiallysqueezed into face to face sealing engagement by the outer annular sealin the sealed condition, and the inner seal elements being radiallyspaced apart to define a passageway between the opposing seal facesthrough the inner seal in the open condition.
 2. The connector of claim1, wherein said one face seal assembly comprises a first face sealassembly which seals the forward end opening of the first contactchamber in the unmated condition of the first connector unit, and asecond face seal assembly seals the forward end opening of the secondcontact chamber in the unmated condition of the second connector unit,the second face seal assembly comprising a second outer annular seal anda second inner seal comprising a second pair of inner seal elementswhich seal the through bore in the second annular seal in the sealedcondition of the second face seal assembly.
 3. The connector of claim 2,wherein the outer annular seal of each face seal assembly has a forwardend face which is in face-to-face sealing engagement with the opposingforward end face of the outer annular seal of the other face sealassembly in the mated condition of the connector units.
 4. The connectorof claim 3, wherein the first outer annular seal is movably mounted inthe first connector unit for movement between an extended position whenthe units are unmated and a retracted position in which it is movedinward when the units are mated, and the second outer annular seal issecured in the second connector unit to engage the first outer annularseal as the units are moved into mating engagement.
 5. The connector ofclaim 4, further comprising a first biasing device urging the firstannular seal into the extended position when the first connector unit isin the unmated condition, the biasing device urging the forward endfaces of the outer end seals into sealing engagement as the connectorunits are moved into mating engagement.
 6. The connector of claim 4,wherein the second inner seal is movably mounted in the second connectorunit for movement between an extended position when the connector unitsare unmated and a retracted position in which it is retracted into thesecond contact chamber when the connector units are mated, and the firstinner seal is in a substantially fixed axial position in the firstconnector unit, whereby the first pair of inner seal elements urge thesecond pair of inner seal elements inwardly into the second contactchamber as the connector units are mated.
 7. The connector of claim 6,further comprising a second biasing device urging the second inner sealinto the extended position when the second connector unit is in theunmated condition.
 8. The connector of claim 2, wherein the contactchambers are filled with fluid and the inner seal elements of the firstand second face seal assemblies are located in the second contactchamber of the second connector unit in the axially displaced, opencondition when the connector units are in mating engagement.
 9. Theconnector of claim 8, wherein the second contact chamber has an innerwall portion spaced from the opposing outer surfaces of the inner sealelements as the connector units are moved into mating engagement,whereby a fluid passageway is provided between the contact chambersaround the inner seal elements as the inner seal elements are displacedaxially relative to the respective outer annular seals and move into thesecond contact chamber.
 10. The connector of claim 2, wherein theforward end face of one of the outer annular seals has a first, innerring portion and a second, outer ring portion, the inner ring portionbeing raised relative to the outer ring portion and being in sealingengagement with the opposing forward end face of the other outer annularseal in the mated condition of the connector units.
 11. The connector ofclaim 10, wherein the forward end face of said one outer annular sealfurther comprises an annular groove separating the inner and outer ringportions of the end face.
 12. The connector of claim 1, wherein the faceseal assembly further comprises a radially directed biasing device whichurges the inner seal elements radially apart in the open position. 13.The connector of claim 1, wherein the through bore of the outer annularseal is tapered along at least part of its length and the opposing outersurfaces of the inner seal elements are correspondingly tapered forsealing engagement in the through bore in the unmated condition of theconnector unit.
 14. A connector, comprising: a first connector unithaving a first contact chamber and a first contact assembly within thefirst contact chamber; a second connector unit having a second contactchamber and a second contact assembly within the second contact chamber;each contact chamber having a forward end opening; the connector unitsbeing movable between an unmated condition and a mated condition inwhich they are in releasable mating engagement and the first and secondcontact assemblies are in communication; at least one elastomeric faceseal assembly which seals the forward end opening of one of the contactchambers in the unmated condition of the connector units, the face sealassembly comprising a first outer annular seal having a through bore anda first inner seal having a first pair of inner seal elements havingouter surfaces and opposing seal faces; one of said seals being movablerelative to the other seal between a sealed condition in which the outersurfaces of the inner seal elements are in sealing engagement with thethrough bore of the outer annular seal when the connector units areunmated and an open condition in which the inner seal elements arespaced from the outer annular seal when the connector units are mated;the opposing seal faces of the inner seal elements being radiallysqueezed into face to face sealing engagement by the outer annular sealin the sealed condition, and being radially spaced apart to define apassageway through the inner seal in the open condition; and the innerseal elements comprising a pair of elastomeric disc halves ofsubstantially half-circular shape each having a substantially flatdiametrical seal face which is in face-to-face sealing engagement withthe opposing flat diametrical seal face of the other disc half when theconnector unit is in the unmated condition.
 15. A connector, comprising:a first connector unit having a first contact chamber and a firstcontact assembly within the first contact chamber; a second connectorunit having a second contact chamber and a second contact assemblywithin the second contact chamber; each contact chamber having a forwardend opening; the connector units being movable between an unmatedcondition and a mated condition in which they are in releasable matingengagement and the first and second contact assemblies are incommunication; at least one elastomeric face seal assembly which sealsthe forward end opening of one of the contact chambers in the unmatedcondition of the connector units, the face seal assembly comprising afirst outer annular seal having a through bore and a first inner sealhaving a first pair of inner seal elements having outer surfaces andopposing seal faces; one of said seals being movable relative to theother seal between a sealed condition in which the outer surfaces of theinner seal elements are in sealing engagement with the through bore ofthe outer annular seal when the connector units are unmated and an opencondition in which the inner seal elements are spaced from the outerannular seal when the connector units are mated; the opposing seal facesof the inner seal elements being radially squeezed into face to facesealing engagement by the outer annular seal in the sealed condition,and being radially spaced apart to define a passageway through the innerseal in the open condition; and the first inner seal further comprisinga base which is axially spaced from the pair of inner seal elements andat least one connecting tine extending between the base and each innerseal element.
 16. The connector of claim 15, wherein the connectingtines are flexible to allow the inner seal elements to move radiallybetween the sealed condition and the open condition.
 17. The connectorof claim 16, wherein the connecting tines comprise a biasing devicewhich urges the seal elements radially outward and away from one anotherinto the open condition in which the seal faces are spaced apart. 18.The connector of claim 15, wherein at least two connecting tines connectthe base to each inner seal element.
 19. The connector of claim 18,wherein the inner seal elements and connecting tines are movableradially outwardly between the sealed condition in which the seal faceof each inner seal element is in face-to-face sealing engagement withthe opposing seal face of the other inner seal element and theconnecting tines are inclined radially inwardly between the base andseal elements, and the open condition in which each inner seal elementis radially spaced from the opposing inner seal element to define saidpassageway and the tines are displaced outwardly at their forward ends.20. The connector of claim 19, wherein the connecting tines are at leastpartially resilient and are deformed to produce a radially outwardlydirected spring force when the inner seal elements are engaged in theouter annular seal.
 21. The connector of claim 15, wherein each innerseal element comprises a rigid back plate and an elastomeric sealportion secured to the back plate.
 22. The connector of claim 21,wherein the base is of rigid material and the connecting tines extendbetween the base and the respective back plates.
 23. A connector,comprising: a first connector unit having a first contact chamber and afirst contact assembly within the first contact chamber; a secondconnector unit having a second contact chamber and a second contactassembly within the second contact chamber; each contact chamber havinga forward end opening; the connector units being movable between anunmated condition and a mated condition in which they are in releasablemating engagement and the first and second contact assemblies are incommunication; a first elastomeric face seal assembly which seals theforward end opening of the first contact chamber in the unmatedcondition of the connector units, the first face seal assemblycomprising a first outer annular seal having a through bore and a firstinner seal having a first air of inner seal elements having outersurfaces and opposing seal faces; one of said seals being movablerelative to the other seal between a sealed condition in which the outersurfaces of the inner seal elements are in sealing engagement with thethrough bore of the outer annular seal when the connector units areunmated and an open condition in which the inner seal elements arespaced from the outer annular seal when the connector units are mated;the opposing seal faces of the inner seal elements being radiallysqueezed into face to face sealing engagement by the outer annular sealin the sealed condition, and being radially spaced apart to define apassageway through the inner seal in the open condition; a second faceseal assembly which seals the forward end opening of the second contactchamber in the unmated condition of the second connector unit, thesecond face seal assembly comprising a second outer annular seal and asecond inner seal comprising a second pair of inner seal elements whichseal the through bore in the second annular seal in the sealed conditionof the second face seal assembly; and the through bore of the firstouter annular seal is tapered outwardly up to the forward end face andthe through bore of the second outer annular seal is tapered inwardly upto the forward end face, and the outer surfaces of the first and secondinner seals are correspondingly tapered for sealing engagement in thethrough bores of the first and second outer annular seals, respectively.24. A face seal assembly for sealing a forward end opening of a contactchamber in a connector unit when the connector unit is unmated,comprising: an outer annular seal which fits in a forward end opening ofa connector contact chamber at least in an unmated condition of theconnector unit, the outer annular seal having a through bore defining alongitudinal central axis of the face seal assembly; an inner seal whichseals the through bore in a sealed position of the outer and innerseals; the seals being relatively movable between the sealed positionand an open position in which the inner seal is displaced out of thethrough bore in the outer annular seal; the inner seal having a pair ofseparate inner seal elements which are spaced apart in the open positionand which are urged together to form an at least substantially disc-likeshape which fills the cross-sectional area of the through bore in theouter annular seal along at least part of the length of the through borein the sealed position, the inner seal elements being configured todefine a continuous outer surface which is in sealing engagement withthe through bore of the outer annular seal in the sealed position; andthe inner seal elements being formed at least partially of elastomericmaterial and each having an inner seal face which is urged by the outerannular seal into face-to-face sealing engagement with the inner sealface of the other seal element in the sealed position.
 25. The sealassembly of claim 24, wherein the through bore in the outer annular sealis tapered and the outer surface of the inner seal elements has amatching taper for sealing engagement in the tapered through bore in thesealed position.
 26. A face seal assembly for sealing a forward endopening of a contact chamber in a connector unit when the connector unitis unmated, comprising: an outer annular seal which fits in a forwardend opening of a connector contact chamber at least in an unmatedcondition of the connector unit, the outer annular seal having a throughbore defining a longitudinal central axis of the face seal assembly; aninner seal which seals the through bore in a sealed position of theouter and inner seals; the seals being relatively movable between thesealed position and an open position in which the inner seal isdisplaced out of the through bore in the outer annular seal; the innerseal having a pair of inner seal elements which together form an atleast substantially disc-like shape which fills the cross-sectional areaof the through bore in the outer annular seal along at least part of thelength of the through bore in the sealed position, the inner sealelements together defining a continuous outer surface which is insealing engagement with the through bore of the outer annular seal inthe sealed position; the inner seal elements being formed at leastpartially of elastomeric material and each having an inner seal facewhich is urged by the outer annular seal into face-to-face sealingengagement with the inner seal face of the other seal element in thesealed position; and the inner seal further comprising a base which isaxially spaced from the inner seal elements and at least one connectingtine extending between the base and each inner seal element.
 27. A faceseal assembly for sealing a forward end opening of a contact chamber ina connector unit when the connector unit is unmated, comprising: anouter annular seal which fits in a forward end opening of a connectorcontact chamber at least in an unmated condition of the connector unit,the outer annular seal having a through bore defining a longitudinalcentral axis of the face seal assembly; an inner seal which seals thethrough bore in a sealed position of the outer and inner seals; theseals being relatively movable between the sealed position and an openposition in which the inner seal is displaced out of the through bore inthe outer annular seal; the inner seal having a pair of inner sealelements which together form an at least substantially disc-like shapewhich fills the cross-sectional area of the through bore in the outerannular seal along at least part of the length of the through bore inthe sealed position, the inner seal elements together defining acontinuous outer surface which is in sealing engagement with the throughbore of the outer annular seal in the sealed position; the inner sealelements being formed at least partially of elastomeric material andeach having an inner seal face which is urged by the outer annular sealinto face-to-face sealing engagement with the inner seal face of theother seal element in the sealed position; and the connecting tinescomprising a biasing mechanism which urges the inner seal elements apartto define a passageway between the seal elements when the inner seal isdisplaced out of the through bore in the outer annular seal in the openposition.